/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.rocketmq.client.apis.message;

/**
 * Abstract message id, the implement must override {@link Object#toString()}, which indicates the message id using
 * string form.
 */
public interface MessageId {
    /**
     * Get the version of the message-id.
     *
     * @return the version of message-id.
     */
    String getVersion();

    /**
     * The implementation <strong>must</strong> override this method, which indicates the message-id using string form.
     *
     * @return string-formed string id.
     */
    String toString();
}
